Spring



SPRING Filed April 27. 1931 FIG. 1

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ATTORNEY Patented Nov. 22, 1932 UNITED STATES CHRISTIAN A. RAsMUssEN, onCLEVELAND, OHIO SPRING Application filed April 27,

My invention relates to an improvement in electrical cont-rollers andmore particularly to contact devices for controllers of the rotatabledrum type, and my object in general is to provide a simple, inexpensive,and durahis contact device, which may be readily installed in close andcompact relation with other co-acting contact parts, and which may beeasily assembled and dis-assembled for convenient inspection, removaland replacement of the parts subject to the greatest wear, allashereinafter shown and described and more concisely set forth in theclaims.

in the accompanying drawing, Fig. 1 is a side elevation of a set of myimproved contact devices or fingers assembled to be installed opposite arotatable switch drum of an electrical controller and Fig. 2 is a frontelevation of Fig. 1. Figs. 3 and 4 are plan and side elevationsrespectively of the resilient means provided for retaining the contactmember in position on the base, and Fig. 5 is a fragmentary sideelevation of the resilient means and locking member showing the mode ofdis-assembling the resilient means from its locking member.

Referring now to the drawing, the present contact device comprises amainbody or supporting member A,,made in two parts 2 and 3,

tightly clamped together by a screw 5. Both parts 2 and 3 are providedwith recessed oppositely arranged seats 6 to grip insulated and roundsupporting rods 7 for securing the contact device in its proper workingposition and part 3 is formed with a bent extremity 5 adapted to serveas a stop or abutment for a set screw 6, carried by a movable contactfinger 9, which rests at its rear end upon an elevated fiat inclinedseat 7 and abuts against 0 an inclined thrust shoulder or extension 8formed on the rear end of part 3. Finger 9 is composed of two flatstrips or pieces riveted together, and the base piece 10 is made ofheavier stock than the superposed strip 11.

Preferably strip 11 is made of copper for better conductivity of theelectric current, which is conveyed thereto from part 3 of supportingmember A by short laminated strips D of copper secured at one end bybolt 12 to 0 part 2 and at its other end by a screw 14 to 1981; Seria1No.- 533,047.

finger. 9i' Finger 9' may turn or pivot on inclined seat '7 and theshort extensionp laminatedzcopper strips D preventingjit from beingdisplaced or disconnected. lniaddis tion, a flat post 15 projectingthrough aslot lfiiformed in the partscomposing finger 9 preventsdisplacement of finger. 9 and. also serves as a: mounting for a shorthelically coiled compression spring '18 which seats upon. finger 9- andencircles post-'15.

The post. l5isformed of' afiat. piece ofsteel having a short stem19-which projects atzone end through a square opening inpart 2 ofsupporting; member A, and: is securely. fas tened against turning byupsettingior riveting. The other-end= of the post tapers in width andhas a hook-shaped head20 adaptedz to interlock with coiled compressionspring 18, so that spring l81applies a yielding. pressure to finger 9to, hold. the contact tip 211 against a. switch drum (not shown) whenthe latter is rotated. in respect thereto. 'Ihus,.the upper uncoiledwire end of helical spring 18 is sharply bent downwardly and upwardly toform a depending, loop-shaped portion or member 22 within theconvolutions of the spring. Member 22 is approximately half the length.of spring 18, when the latter is not under compression and. includes twoparallel. arms 23 and 24-, connect.- ed at their lower ends by thebridge or cross piece 25 of the loop. The free arm 2 Lv of member 22 issharply bent downwardly to form a short hook 27 for engagement with theupper convolution of spring 18, when the latter is seated uponfinger 9and coupled with head 20 of post 15,, thus insuring axial alignment ofloop-shaped. member 22- and spring 18underall conditions.

The described shape and form of. spring member 18 and its looped member22 permits of' ready attachment or detachment thereof during assemblyand disassembly of my contact device. To assemble, finger 9 is sleevedover head 2.0,and the open endof spring 18 is sleeved upon. head 20- insuch a position that when: the spring is manually compressed, bridge 25will readily engage with the recessed or hook portion of head 20. Uponrelease of pressure the spring 18 will expand and cause the parts tointerlock. In dis-assembling operations spring 18 and head 20 aredisconnected by local pressure applied to one side of the upper coil ofspring 18, which creates buckling of the coil, under which hook member22 has a tendency to move away from the recessed portion of head 20, asclearly disclosed in Fig. of the drawing.

Strip 11 1S slightly ofiset rom base strip at lts outer extremities toprovide a seat for the flat extension 26 of copper contact tip 21, ascrew 40 being employed to connect the extension tightly between theends of the strips. A bent spring 27' riveted to contact r 9 adjacentthe set screw 6 serves to Ice this set screw against accidental turningafter proper adjustment has been made.

A lug 29 for attaching a terminal member to body A is secured toextension 28 of member A by screw-bolt 12.

It will be obvious that the spring 18 may be advantageously employed foreffecting 'elding connection between any co-operatparts which arepivotally interlocked with each other or are parallelly movable withrespect to each other, and therefore I do not wish to restrict the useof such spring and its co-operating hook member to the particular switcharrangement disclosed. 30 What I claim, is:

1. As an article of manufacture adapted to yieldin 1y connect a seriesof members having partly intersleeved portions, a compression springseated upon one of said portions and partly sleeved over the other ofsaid portions, said splring including integral, freely and lateria yshiftable locking means extending from one end of said spring into itshollow rtion to the center thereof for readily reeasable engagement withthat portion over which it is sleeved.

' 2. As an article of manufacture for yieldingly connecting partlyintersleeved members, a compression spring comprising a main spring bodand an integral elongated loop of less wi th than the interior diameterof said spring, extending from one end of said 8 ring axially into itsmain body to the center ereof.

3. As an article of manufacture for yieldingly connecting partlyintersleeved members, a compression spring comprising a main body havingan integral elongated loop portion of substantial less width than theinterior diameter of said spring and formed with parallel leg portionsdownwardly extending into the body of the spring to the center thereof,one of said leg portions being an hooked to the upper coil thereof foraxial alignment with the main body of said spring.

testimon whereof I afiix my signature. 0 STIAN A. RASMUSSEN.

